Eastern green mamba
Eastern green mamba | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Reptilia |
Order: | Squamata |
Suborder: | Serpentes |
Family: | Elapidae |
Genus: | Dendroaspis |
Species: | D. angusticeps
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Binomial name | |
Dendroaspis angusticeps | |
geographic range
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Synonyms[3] | |
List
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The eastern green mamba (Dendroaspis angusticeps) is a highly
In spite of common urban legends and misconceptions labeling the eastern green mamba an aggressive, fast-moving “people-chaser”, it is in fact a shy and elusive species that remains hidden in the trees, and is rarely seen. This seclusion is usually attributed to its arboreal
.Eastern green mamba
Taxonomy
The eastern green mamba was first described as Naja angusticeps by Andrew Smith, a Scottish surgeon and zoologist, in 1849, who reported it from Natal and east to Maputo Bay.[4] The specific name angusticeps is derived from the Latin word angustus, "narrow",[5] and ceps, an abbreviated form of caput ("head") when used in a compound word.[6] The German-British zoologist Albert Günther described Dendroaspis intermedius from the Zambezi River in northern Mozambique in 1865.[7] This was subsequently synonymised with D. angusticeps.[8]
In 1896, the Belgian-British zoologist
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As well as being called the eastern green mamba, the species is also frequently known as the common green mamba, East African green mamba, white-mouthed mamba, or simply the green mamba.[15]
Description
The eastern green mamba is a large snake, with a slightly compressed and very slender body with a medium to long tapering tail. Adult males average around 1.8 metres (5 ft 11 in) in total length, while females average 2.0 metres (6 ft 7 in). This species rarely exceeds lengths of 2.5 metres (8 ft 2 in). In general, the total length is 4–4.3 times the length of the tail.[16][17][18] The adult eastern green mamba has bright green upperparts—occasionally with isolated yellow scales—and a pale yellow-green belly. Sometimes they are duller-coloured before moulting. Juveniles are blue-green, becoming bright green when they are around 75 centimetres (2 ft 6 in) long.[17] The coffin-shaped head is long and slender, with a prominent canthus which is slightly demarcated from the neck.[18] When threatened or otherwise aroused, the eastern green mamba is capable of flattening its neck area into a slight hood.[19] The medium-sized eyes have round pupils,[18] the borders of which have a narrow golden or ochre edge; the irises are olive green, becoming bright green posteriorly. The inside of the mouth may be white or bluish-white.[16]
Other green snakes are often called "green mambas" in Southern Africa, including green forms of the boomslang (Dispholidus typus), which can be distinguished by their larger eyes and shorter heads. They are also venomous. Green bushsnakes of the genus Philothamnus[17] are also commonly confused with smaller Eastern green mambas.
Scalation
The number and pattern of scales on a snake's body are a key element of identification to species level.
Distribution and habitat
The eastern green mamba is native to regions near the coastlines of Southern Africa and East Africa. Its range extends from Kenya south through Tanzania, Malawi, eastern Zimbabwe and parts of Zambia; it can also be found in Zanzibar and northern Mozambique.[15][16] An isolated and genetically distinct population is found in South Africa from the extreme northeastern part of Eastern Cape along the KwaZulu-Natal coastline and into southern Mozambique.[8]
An elusive species, it is primarily
Conservation status
The species' conservation status has not been assessed by the International Union for Conservation of Nature (IUCN). It is fairly common throughout its range, and populations are believed to be stable. Large concentrations of two to three individuals per hectare have been documented in coastal Kenya and southern Tanzania, and in one instance a group of five were seen in a single tree. Although populations are stable overall, habitat destruction and deforestation may pose a threat.[18] In South Africa, it is rated as "vulnerable" as its habitat had become highly fragmented by coastal housing development.[8]
Behaviour and ecology
A diurnal species, the eastern green mamba is active by day and sleeps at night coiled up in foliage or rarely a hollow within the trunk or branch.[17][15] An agile snake and an adept climber, it is not commonly found on the ground though may come down to bask in the morning sun (thermoregulation).[18] A 27-day study of the movement patterns of two adults found their activity area to be relatively small, comparable to other predators who ambush prey rather than hunt (in contrast to most elapid species, including other mambas, who tend to hunt and forage). The study's preliminary evidence shed light on the species' feeding methods, suggesting it may be primarily an ambush predator due to its sit-and-wait behaviour. This evidence does not preclude active foraging, however; a specimen was also observed systematically hunting a sleeping bat.[24]
There is no evidence that the eastern green mamba migrates. Thought to be relatively sedentary, it can remain in the same location for days, apparently moving most commonly to find food or mates. On average, individuals move only about 5.4 metres (18 ft) per day.[22][24] They generally avoid contact with people and other predators, attacking them only if they feel threatened.[15]
Reproduction and lifespan
The eastern green mamba is
Males locate females by following a scent trail. The male courts the female by aligning his body along the female's while rapidly tongue-flicking. If the female is receptive to mating, she lifts her tail; cloacal juxtaposition follows. Courtship and mating take place in trees, after which the female can lay 4–17 eggs (10–15 on average), occurring in October and November.[22] The eggs are small and elongated, usually 47–58 x 25–28 mm,[16][17] and usually laid in leaf litter in hollow trees.[17] The incubation period is around three months.[18] When the young emerge, they are approximately 30 to 45 cm (12 to 18 in)[17] in the wild, and 44 cm (17 in) in captivity.[22] They usually reach adult colouration at 75 cm (30 in).[16][17] Hatchlings tend to grow to 50 to 80 cm (20 to 31 in) in their first year. As they age, their growth rates decrease but never completely stop.[22]
The oldest recorded eastern green mamba was a captive specimen that lived 18.8 years.[25] Another captive specimen lived 14 years.[23]
Diet
The eastern green mamba preys primarily on birds and their eggs, and small mammals including bats. It is also believed to eat arboreal lizards.[16][17] It uses a sit-and-wait strategy, though one specimen was recorded actively hunting sleeping bats.[24] The species is also known to raid the nests of young birds.[26] Sit-and-wait tactics may be successful with highly mobile prey, such as adult birds or rodents. Documented prey include the sombre greenbul, which occur in dense areas of natural and cultivated vegetation along Kenya's coastline. Ionides and Pitman (1965) reported a large bushveld gerbil in the stomach of a green mamba in Tanzania. Although the bushveld gerbil does not occur in Kenya, green mambas prey on the seven species of gerbil that inhabit parts of its range.[24]
Predators
The eastern green mamba has few natural predators. Humans, mongooses, snake eagles and genets commonly prey on it, and hornbills and other snakes prey on juveniles.[24]
Venom
The eastern green mamba has the least toxic venom of the three green mamba species, but it is still highly
Symptoms of envenomation by this species include pain and swelling of the bite site, which can progress to local necrosis or gangrene.
In 2015, the
Similarly to the venom of most other mambas, the eastern green mamba's contains predominantly three-finger toxin agents. The exception is the black mamba, whose venom lacks the potent
Treatment
Standard first aid treatment for any bite from a suspectedly venomous snake is the application of a pressure bandage, minimisation of the victim's movement, and rapid conveyance to a hospital or clinic. Due to the neurotoxic nature of green mamba venom, an arterial
Notes
References
- . Retrieved 18 September 2021.
- ^ "Dendroaspis angusticeps". Integrated Taxonomic Information System. Retrieved 30 October 2012.
- ^ Uetz, Peter; Hallermann, Jakob. "Dendroaspis angusticeps (SMITH, 1849)". The Reptile Database. Reptarium association. Retrieved 17 February 2012.
- ^ Smith, Andrew (1849). Illustrations of the Zoology of South Africa, Reptilia. Vol. 4. London: Smith, Elder and Co. Plate 70.
- ISBN 978-90-04-16797-1.
- ^ Hall, Whitmore (1861). The principal roots and derivatives of the Latin language, with a display of their incorporation into English. London: Longman, Green, Longman & Roberts. p. 153.
- .
- ^ ISBN 978-1-919976-96-9.
- ^ Boulenger, George Albert (1896). Catalogue of the snakes in the British Museum (Natural History). Printed by order of the Trustees British Museum (Natural History). Department of Zoology. p. 437.
- ^ FitzSimons, V. (1946). "Notes on some south African snakes, including a description of a new subspecies of Xenocalamus". Annals of the Transvaal Museum. 20: 379–393 [392–393].
- .
- ^ Loveridge, Arthur (1950). "The green and black mambas of East Africa". Journal of the East Africa Natural History Society. 19 (5): 251–252.
- PMID 27603205.
- ^ S2CID 217018550.
- ^ a b c d "Dendroaspis angusticeps". WCH Clinical Toxinology Resource. University of Adelaide. Retrieved 26 April 2014.
- ^ ISBN 978-0-00-212146-0.
- ^ ISBN 978-1-8-6872-932-6.
- ^ ISBN 978-0-88359-029-4.
- ^ Pitman, Charles R.S. (1965). "Hood-spreading by the mambas of the African genus Dendroaspis Schlegel". Journal of East African Natural History. 25 (2): 110–115.
- ^ Hutchinson, Mark; Williams, Ian (2018). "Key to the Snakes of South Australia" (PDF). South Australian Museum. Government of South Australia. Retrieved 8 February 2019.
- ^ Macdonald, Stewart. "snake scale count search". Australian Reptile Online Database. Retrieved 3 May 2019.
- ^ .
- ^ ISBN 978-1-86825-575-7.
- ^ a b c d e Angilletta, Michael J. (1994). "Sedentary behaviors by Green Mambas Dendroaspis angusticeps" (PDF). Herpetological Natural History. 2 (2): 105–111. Archived from the original (PDF) on 3 March 2016. Retrieved 26 April 2014.
- ^ "AnAge entry for Dendroaspis angusticeps". AnAge:The Animal Ageing and Longevity Database. Human Ageing Genomic Resources. Retrieved 26 April 2014.
- ISBN 978-0-71-372114-0.
- ISBN 978-0-691-12436-0.
- ^ PMID 11990107.
- PMID 7244896.
- ISBN 978-0-398-03051-3.
- ^ Mazza, Giuseppe (2011-04-27). "Dispholidus typus". Monaco Nature Encyclopedia. Retrieved 2022-07-09.
- ^ a b c Müller, G. J.; Modler, H.; Wium, C. A.; Veale, D. J. H.; Marks, C. J. (2012). "Snake bite in southern Africa: diagnosis and management". Continuing Medical Education. 30 (10): 362–381 [362, 380–381].
- ^ PMID 26877184.
- PMID 8302860.
- ISSN 2073-9990.
- S2CID 4916503.
Further reading
- Access Professional Development. 2022. Green Mamba (Dendroaspis angusticeps) [Online] Available: https://accesspd.co.za/species/GreenMamba Archived 2022-02-02 at the Wayback Machine (Accessed: 02/02/2022)
External links
- Media related to Dendroaspis angusticeps at Wikimedia Commons
- Data related to Dendroaspis angusticeps at Wikispecies